import sysconfig
from multiprocessing.pool import ThreadPool

def thread(i):
    assert sysconfig.get_config_var("srcdir") is not None

with ThreadPool() as pool:
    pool.map(thread, range(100))

Traceback (most recent call last):
  File "/home/grees/core/junk.py", line 8, in <module>
    pool.map(thread, range(100))
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/grees/github.com/cpython/Lib/multiprocessing/pool.py", line 364, in map
    return self._map_async(func, iterable, mapstar, chunksize).get()
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/grees/github.com/cpython/Lib/multiprocessing/pool.py", line 771, in get
    raise self._value
    ^^^^^^^^^^^^^^^^^
  File "/home/grees/github.com/cpython/Lib/multiprocessing/pool.py", line 125, in worker
    result = (True, func(*args, **kwds))
                    ^^^^^^^^^^^^^^^^^^^
  File "/home/grees/github.com/cpython/Lib/multiprocessing/pool.py", line 48, in mapstar
    return list(map(*args))
           ^^^^^^^^^^^^^^^^
  File "/home/grees/core/junk.py", line 5, in thread
    assert sysconfig.get_config_var("srcdir") is not None
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError